Stitcher heads for signature machines



United States Patent Lawrence J. Werstler;

Jerome T. Jablonski, Jr., Chicago, Illinois 752,260

Aug. 13, 1968 Nov. 24, 1970 Chicago Machinery Laboratories, Inc. Chicago, Illinois a corporation of Illinois lnventors Appl. No. Filed Patented Assignee STITCHER HEADS FOR SIGNATURE MACHINES 2 Claims, 9 Drawing Figs.

US. Cl 227/90 Int. Cl B25c 5/08 Field oi'Search 227/87, 88,

[56] References Cited UNITED STATES PATENTS 1,252,011 1/1918 Maynard....

Primary Examiner-Granville Y. Custer, Jr. Attorney-Kinzer, Dorn and Zickert 12/1934 McClure 2/1967 McCainetal.

ABSTRACT: Operation of a stitching head in a signature machine for a no-stitch or stop-stitch circumstance is'improved, and certain parts in the prior construction are eliminated by a minor but nonetheless effective alteration in the known driver bar.

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Patented Nov. 24, 1970 3,542,271

Invent) rS Lawrence J. Werstler Jerome T. JablonskiJn KWQDM Mr 24% fi-Hrornew Patented Nov. 24, 1970 4 Inventors Lawrence lWersfler Jerome T. Ja b lonski Jr. a KA'My Dm and 2M RH- 0 megs Patented Nov. 24, 1970 3,542,271

Sheet 4 of 4 Inventors Lawrence J. Werstler Jerome 'EJabloxzski, Jr.

STITCIIER HEADS FOR SIGNATURE MACHINES A signature gathering and stitching machine is an example of an instance where a stitcher head, normally effective to apply a staple, may be so controlled as to disablewire feed characterizing a no-stitch condition. An example of a signature machine operating in accordance with this principle is disclosed in McCain U.S. Pat. No. 3,305,154, satisfactory performance of which has been established in actual use. In the McCain machine, the no-stitch (no staple) condition is established by uniquely interrupting motion of the bender bar in a known stitching head so that the bender bar is not permitted to attain the position characteristic of the wire being gripped for the following cycle in which wire for forming a staple would ordinarily be fed to the staple forming position. The attainment of this end required additional alterations in the known structure, and the primary object of the present invention is to further improve rid-stitch operations and toachieve a simplified no-stitch construction by an alteration in the driver bar which eliminates the need for certain driving elements as presented in McCain U.S. Pat. No. 3,305,l54. While the embodiment of the present invention is concerned primarily with the occurence of events in a signature gathering and stitching machine, it is to be emphasized that this is but one example of utility, which is to say that the invention may be adopted in other structures where it is desired to eliminate the feeding of wire to stitching position.

Other and further objects of the present invention will be apparent from the following description and claims, and are illustrated in the accompanying drawings which,by way of illustration, shows a preferred embodiment of the present invention and the principle there I" and what is now considered to be the best mode contemplated for applying that principle. Other embodiments of the invention embodying the same or equivalent principle may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention.

In the drawings:

FIG. I is an exploded perspective view of certain elements representing structure of the present invention;

FIG. 2 is a plan view of the driver bar shown in FIG. 1;

FIG. 3 is an elevation on the line 3-3 of FIG. 2;

FIGS. 4, 5 and 6 are'views illustrating the interrelationship of operating parts under different circumstances of control;

FIGS. 7 and 8 are exploded perspective views representing the prior art; and

FIG. 9 is a view showing the manner in which the present invention may be practiced in terms of the stitching of signatures.

In McCain U.S. Pat. No. 3,305,154 actuating means for the stitcher head of a signature stitching (book stitching) machine is limited by an interposer member which in turn so limits the stroke of the driver bar inthe stitcher head as to retain the wire grip means of the wire'feed mechanism in an open, nonclamping position representing the no-stitch event. The event is to occur as an incident to a determination that the book delivered to the stitcher head is determination is made by a caliper which measures the thickness of each book passing through the machine. In the event the caliper detects a book which is too thick or too thin (too many, or not enough signatures in the signature group as the case may be) a control signal or condition is established ultimately manifest in positioning said interposer member to limit the action of the driver bar as mentioned above.

The stitcher head is the well-known BOSTITCH stitcher,

' models 26 or 26D, constructed in accordance 'with the disclo sure in U.S. Pat. Nos. 1,252,011 and I,983,384. In .this stitcher, assuming a vertical orientation and consequent vertical reciprocationof thebender bar and driver bar in the stitcher, the wire grip is open during the major portion of the upstroke of the driver bar but closes to grip the wire at the incremental position slightly before the driver bar arrives at top dead center. This wire grip state prevails during the next downstroke of the bender bar and driver bar, to feed the wire for forming a staple in the book located beneath the stitcher head; but at bottom dead center of the driver bar the wire grip is open, and this grip-open circumstance prevails on the next upstroke until'the incremental position aforesaid is attained. If the book is a bad book, actuation of the interposer member, under the principles of the McCain patent, prevents the driver bar from completing its upward stroke to top dead center position, thus maintaining the wire grip in open position during the next downstroke when it would be normally closed for feeding wire to form a staple.

It is also helpful to an understanding of the present disclosure that in normal operation the bender bar at its bottom dead center position clinches the wire which was normally both fed and cut in the previous stroke. Thus, for a particular staple, the wire is fed and cut in one downstroke, and on the next downstroke the staple is pressed home and formed or clinched to the signature group representing a good book of correct thickness.

The prior art to which the present invention is directed is represented by aforesaid McCain U.S. Pat. No. 3,305,l54, and in particular FIGS. 9 and 10 of the McCain patent which are here presented as FIGS. 7 and 8. The same reference characters as in the patent are used in the present drawings to explain the improvement here achieved.

As shown in FIG. 7 hereof, a wire gripper jaw 44 is received for horizontal shifting movement in the slot 485 of a block or anvil 48 which in turn is rigidly secured to the bender bar 50.

The block 48 in fact may be integral with the bender bar FIG.

8. In any event, the gripper has a serrated jaw 44S adapted to grip or clamp the wire to the opposing surface in the anvil 48 presenting the slot 488.

A spring 52 projecting from the bender 50 extends through a slot at the left-hand side of a latch and into an aperture 44A in the gripper jaw 44. The spring 52 is quite strong and normally holds jaw 44 in its wire grip position.

The latch 55 is mounted for horizontal sliding action in a slot 508 in the bender bar 50 and embraces a driver bar 54 which slidably fits in a vertical channel 50C in the bender bar. The driver bar has an upper slot 54U and a lower slot 54L formed along one vertical edge thereof. Slot 54L is deeper than slot 54U. When slot 54U in the driver bar 54 is aligned with the left leg portion of the latch 55, the driver holds the latch in a leftmost position as can be imagined from FIG. 7,

bending spring 52 to the left and holding the gripper 44 away from the wire.

Slot 54L formed in the same side of the driver 54 is deeper than slot 54U. When driver 54 presents slot 54L to the latch, spring 52 takes over and urges the gripper 44 to a closed position, clamping the wire against the right-hand anvil wall in the block 48 defining the slot 485 with sufficient force to feed the wire downwardly when the driver bar 54 carries the bender bar 50 downwardly.

of incorrect thickness. Such The driver bar 54 is driven vertically by means to be described, and this motion of the driver is transmitted to the bender bar so that the bender bar is driven by the driver 54. This is achieved by a pin 60? projecting through an aperture 50H in the bender bar, the pin being held forcefully against the rear face of the driver 54 by a spring 605 supported on a spring holder 60H. In this manner, the bender bar is driven frictionally by the driver.

The driver 54in turn is driven by a spring slide 27 formed at its lower end with a notch 27A, FIG. 8, in which is fitted a shoulder 54A on the upper end of the driver 54. Thus, when the slide 27 is reciprocated (See U.S. Pat. No. 1,252,011) the driver 54 is reciprocated, and the driver 54 reciprocates the bender bar 50 through the friction pin or plunger 60F.

The upper end of the slide 27, FIG. 8, has a pin or key 26 projecting rearwardly therefrom. This key fits in a corresponding groove 28 in a driver lever 20, FIG. 9, which is oscillated by a drive link 19. In normal operation, under McCain U.S.

'Pat. No. 3,305,154, reciprocation of link 19 is transmitted to member is set to an actuated position as disclosed in the Mc- Cain patent, limiting the upstroke'of the slide 27 so that the driver bar 54 will not attain the incremental position where the wire gripper closes-on the wire just before top dead center position. This means that the driver 54, FIG. 7, was not allowed to reach top dead center to present slot 54L to the latch 55. However, and to assure instant and positive response of the bender bar 50 to the downstroke of the driver bar 54 in the next cycle, elements shown in FIG. 8 hereof were required including a key 201 which is interposed between a shoulder 205 on the bender bar and a shoulder 208 on the driver bar. Satisfactory operation of this arrangement has been proven in actual use, but we have now found that such parts, FIG. 8, can be eliminated, while attaining superior performance, less cost and lessmaintenance, by an alteration in the geometry of the bender bar as will now be described.

Referring to FIG. I, the altered driver bar of the present invention is identified by reference character 54,. It will be noted first of all that the configuration on the right-hand side, presenting the shoulder 208 has been eliminated, whereas the shoulder or tongue 54A, mentioned above in connection with the prior art, has been retained to establish the desired connection to the spring slide 27, FIG. 9. No material alteration is made in the bender bar 50, FIG. I, and in fact the spring 52 is retained along with the slot or guide 505 in which the latch 55 fits and the channel 50C in which the driver bar is nested.

The left-hand side of the driver bar 54' is configured to present an upper slot 54L) and a lower slot 54L. The upper slot 54U? is the most shallow slot and will bias the latch 55 to its no-grip position, whereas the deepest slot 54L will permit spring 52 to shift the wire grip to its wire gripping position as described in McCain U.S. Pat. No. 3,305,154. Thus when the parts shown in FIG. 1 are combined, the driver bar 54' will fit in the channel 50C of the driver bar, the latch 55 will embrace the thus fitted driver bar while nested in the slot 505, and the spring 52 will extend through the notch 55N at the left-hand side ofthe latch 55 as viewed in FIG. 1.

As in the known structure, the gripper jaw 44, FIG. 4, fits in the gripper jaw block 48, having a serrated or tooth side 44$ for clamping the wire to the anvil 48. Thus, so far as concerns the mounting of the driver bar in the bender bar and the rela- 4 tion of the latch 55 to the gripper 44 and the anvil 48, and in terms of the effectiveness of the spring 52, the relationship is as shown in FIG. 7 hereof and as explained in McCain U.S. Pat. No. 3,305,154. Thus, both the gripper 44 and the latch 55 are adapted to shift along axes that are parallel to one another but which are transverse to the axis of motion of the bender bar and the driver bar.

Under and in accordance with the present invention, a third slot 54T, FIG. 2, is formed in the driver bar 54' at a position intermediate the upper and lower slot. The third slot thus provided presents a driving shoulder 54H, FIG. ll, to'gether with a stop shoulder 54F, FIG. 2, which, when presented to the latch 55, cooperate to both hold the wire grip 44 in an ineffective position while establishing a positive drive from the drive bar 54 to the latch 55, and from the latch 55 to the bender bar 50, bearing in mind that the latch 55 is nested in the bender bar and hence is itself able to drive the bender bar. The slot 54T as thus provided eliminates the need for separate elements for establishing a positive drive between the drive bar and the bender bar when no wire is to be fed. In this connection, FIG. 2, it will be observed that the depth of the slot 54T is substantially the same as the depth of the slot 54U', but is not as deep as the slot 54L.

As disclosed in McCain U.S. Pat. No. 3,305,154, motion of the bender bar in its vertical reciprocation is limited by what amounts to the length of the window opening 43W, FIG. 4 hereof. formed in the face plate 46 of the stitcher head. Thus in the course of vertical movement of the bender bar, engagement of'the upper edge of the anvil block 48, FIG. 4, with the top edge of the window 43W stops the bender bar in this position, and in like manner engagement of the lower edge of the block 48, FIG. 5, with the bottom edge of the window opening 43W limits downward motion of the bender bar 50 to this extent. On the other hand, the drive bar 54' has extended motion in each direction.

In FIGS. 4, 5 and 6 the various positions of the driver bar, corresponding to the limit positions of the bender bar, are illustrated in terms of the top dead center position of both parts, FIG. 4, the bottom dead center position of both parts, FIG. 5, and the stop stitch or no-stitch position, FIG. 6.

Thus FIG. 4 illustrates the position of the bender bar 59 as well as the driver bar 54 when these two parts are in their top dead center position as a feature of normal operation. Under this circumstance, the lower slot 541. is presented to the latch 55. The slot 541., as the slot 54U', is at least as wide as the adjacent leg portion of the latch. This being so, the latch shifts toward the driver bar and spring 52 is allowed to force the gripper 44 to its wire grip position. On the next down stroke of the driver bar and the bender bar, wire is fed for forming a taple in the next cycle of machine operation.

In FIG. 5 the bender bar and the driver bar are shown in the positions they occupy in the bottom dead center position. The driver bar 54 was extended in its downward travel beyond the stop position of the bender bar, and as this occurred latch 55 was first cammed to the left to travel over the two shoulders 54? and 54H and escape past the rise 54R, finally snapping into slot 54U under the urging of spring 52. It will be recognized that the rise 54R separates the upper slot 54-U' and the intermediate slot 541". 'Preferrably, adjacent surfaces are sloped somewhat to facilitate escape.

When wire feed is to be interrupted, the bender bar 5t nonetheless will assume its top dead center position, FIG. However, the interposer member disclosed in McCain U.S. Pat. No. 3,305,154 is actuated to limit the driver bar 54 in its upstroke to the relative position shown in FIG. 6 wherein the driver bar is prevented from moving through the tiny increment of upward motion required to present slot 54L to the latch. This means that the driver bar 54' presents its third or intermediate slot 54T to the adjacent leg of the latch, wherein the stop shoulder 54F abuts the latch leg and prevents spring 52 from being effective to urge gripper 44 to its wire grip position. At the same time, the square shoulder 54H of the driver bar embraces the shoulder 55L of the latch, FIGS. 1 and 6, sufficiently to drive the latch downward the instant the driver bar is driven downward from its position shown in FIG. 6. Since the latch is nested in the bender bar, the latch acts as a key between the driver bar and the bender bar, making it unnecessary to resort to the keying arrangement shown in FIG. 3.

It will be seen from the foregoing that by adding the third slot or notch in the side of the driver bar to present the shoulders 54H and 54?, elements required under the prior art are rendered obsolete and unnecessary. Thus by presenting a third slot in the same side of the driver bar as the slots 54U' and 54L, a stop shoulder 54? is afforded which will maintain the latch 55, when a third slot of the driver bar 54' is presented thereto, in a position where the latch 55 prevents the spring 52 from being effective to press the gripper jaw 44 to its wire gripping position. At the same time, the horizontal shoulder 54H of the driver bar 54' rests on the upper corner portion of the left-hand leg 55L of the latch bar 55, whereby the driver bar 54 is keyed to the latch 55. Both legs of the latch 55 are always in corresponding notches or slots 508 in the bender bar 50, which is to say that the legs of the latch 55 are neatly embraced by the walls of the bender bar which define the slots 508. Therefore, the latch 55 is keyed to the bender bar, and when the driver bar is driven downwardly under the circumstance shown in FIG. 6, the bender bar will be driven downwardly at the same time, and there is no need to rely upon the key structure of the prior art illustrated in FIG. 8 hereof.

the upper slot 54U' is presented to the leg 55L of the latch,

but we prefer to use the interposer cam identified by reference character 145 in US. Pat- No, 3,305,l54, disclosure of which is incorporated by reference herein.

Hence while we have illustrated and described a preferred embodiment of our invention it is to be understood that this is capable of variation and modification within the purview of the following claims.

We claim:

1. in a staple forming stitcher head, a shiftable gripper jaw and an opposed anvil carried by a bender bar and between which is fed the wire for forming the staple, a spring normally urging the gripper jaw to its wire gripping position,a slidable latch carried by the bender bar and engageable with the spring to influence the effective action of the spring depending upon the shifted position of the latch, a driver bar controlling the position of the latch and movable in opposite directions along an axis transverse to the shift axis of the latch, said driver bar having an edge bearing against an opposed portion of the latch, said spring being effective to urge said portion of the latch into contact with said edge of the driver bar, and said edge of the driver bar presenting a plurality of slots for receiving said portion of the latch under the urging of said spring, a first one of said slots being the deepest slot and which allows the spring to force the gripper to its wire gripping position when said portion of said latch is received in said first slot, a

second of said slots being the most shallow slot and which prevents the spring from forcing the gripper to its wire gripping position when said portion of said latch is received in said second slot, and a third of said slots being located between the other two and which is of such depth as to also prevent the spring from forcing the gripper toits wire gripping position when said portion of said latch is received in the third slot, said third slot presenting a shoulder bearing on an opposed shoulder of the latch when the latch is at the third slot so that the latch keys the driver bar to the bender bar.

2. A stitcher head according to claim 1 incorporated in a signature stitching machine having means to reciprocate the driver bar relative to the latch, and means to limit such relative movement of the driver bar to the location where the third slot rather than the first slot is presented to the latch shoulder. 

